Sound-box for talking-machines.



H. SHEBLE.

SOUND BOX FOR TALKING MACHINES.

APPLICATION FILED MARIE. I915.

mwwm. muted (hot. 26, 1915.

INVKNTb H RA E HE kE 57 vs TTbRNE HORACE SHEBLE, OF PHILADELPHIA, PENNSYLVANIA.

SOUND-B 0X FOR TALKIN G-MAGHIN ES.

Specification of Iietters Patent.

Patentedfict. 2c, ire-i5.

Application filed March 5, 1915. Serial N 0. 12,245.

Toallw/wmit may concern: 1

Be it known that 1,. Homer. SHEBLE, a citizen of the United States, residing in Philadelphia, Pennsylvania, have invented. certain Improvements in Sound-Boxes for' 'lalking-Machines, of which the following is a specification. l

The object ofmy invention is to so construct a talking machine sound box as to. tend t. maintain in one position the lever which carries the stylusor needle and to return said lever to'such position when it has been deflected therefrom. This object I attain in the manner hereinafter set forth, reference being had to the accompanying drawing, in which- Figure 1 is a face View, on enlarged scale, of a sound box constructedin accordance with my invention; Fig. 2 is an edge view of the same, looking in the directionof the arrow Fig. 1; Fig. 3 is a transverse section of the sound box and part. of the tone arm connected thereto, and Fig.4 is a sectional view on the line (;-c, Fig. 2.

The construction of the sound box is shown in Fig. 3, on reference to which it will be observed that the hollow body of the box contains the usual diaphragm 2 the peripheral portion of which is confined between rings 40 and -41 of rubber or other elastic material, the supporting ring 40 which contacts with the inner face of the diaphragm being contained in a groove in the base of the sound box and the confining ring 41 which bears upon the outer face of the diaphragm being held in contact therewith by tha annular cap or cover plate 2". The base of the sound box has a curved passage 2 which communicates with the tonearm 3 and the bearing head at the inner end of the needle carrying lever 42 rests upon or is secured to the center of the diaphragm above the entrance. to said passage 2, as shown in Figs. 1 and 3. 1

The needle carrying lever 42 has an on larged head 43 in which is formed the socket forthe reception of the needle, the latter being secured in place by means of a confining screw 44, and the needle carrying lever is retained in its normal position by reason of its engagement with. the elastic fulcrum members, the opposite sides of the head 43 of the needle carrying lever having formed therein V-shaped recesses for the reception of the Vshaped nds of the inturned upper portions 45 of the side members 46 of an elastic yoke whose base member 47 is secured to. an arm' 48 projecting from the sound box 2, this method of mounting the needlecarrying lever being best shown in Figs. 1, 2 and 4 of the drawing.

Connecting the opposite arms 46 of the elastic yoke is a bolt 50 having at one' end a head 51 and at the other end a nut.52, the latter being adapted to the threaded end of the bolt so that by adjustment. of the nut the pressure of the V-shaped ends of'the members 45 of the yokecan be varied, the elasticity of those portions of the yoke intervening between its bearing points and the bolt 50, however, constituting a factor in the vibratory movements of the needle lever.

That portion of the needle lever 42 intervening between the fulcrum of the lever and its point of contact with the sound box diaphragm 2 is so much greater than the distance between the fulcrum of the lever and the point of the needle carried thereby 'as to properly amplify the vibrations imparted to the needle.

The V-shaped ends of the spring contact fulcrum of the needle carrying lever bite into the latter and cause its vibrations to be imparted to the spring, whose torsional resistance thus tends to constantly maintain the lever in one position and to return it to such position when it has been deflected therefrom, the result being a prompt response of the needle to the conformation of the record groove and a' correspondingly perfect reproduction of the sounds from which the record was produced.

/ I claim:

1. A talking machine sound box having a needle carrying lever with a frictional spring contact fulcrum which exercises "torsional control of the lever.

2. A talking machine sound box having a needle rarrying lever,- with a frictional spring contact fulcrum comprising elastic fulcrum .members having pointed ends which are caused to engage the sides of the needle carrying lever.

3. A talking machine sound box having a needle carrying lever with a pointed frictional spring contact fulcrum which exer cises torsional control of the lever.

4. A talking machine sound box having a needle carrying lever, with a spring con tact fulcrum comprising elastic fulcrum members having pointed ends which are caused to engage the sides of the needle carryi g lever, and means for varying the pressure of said pointed ends against the lever.

A talking machine sound box having a needle carrying lever, and an elastic vol e having inturned arms which engage said lever and serve. as a lulerum theret'or \vhieh exercises torsional control of the lever.

(3. A talking maehine sound hox having av easing, a diaphragm, means for retaining said diaphragm atits peripheral portion, a needle earrving "lever, and a frietional spring eontaet tulerum for the latter \vhieh exereises torsional eontrol of the lever.

7. A talking maehiue sound hox having a needle earr \;'ing le\'er,'and an elastie fulcrum for the latter, comprising opposite elastic members having pointed ends which are caused to engage the sides of the needle carrying lever and serve to transmit the vibratory moveuwnts ol' the latter to said fulcrum.

S. A talking maehine sound hox having a needle earrying lever. and an elastie l'ulerum mounting for the latter comprising elastic fulerum memhers having pointed ends \vhieh are eaused to engage the. sides of the needle rarrying lever aml tend to maintain said lever in one position and also to return it to such position when detieeted therefrom. I 1

In testimony whereof, I have signed my name to this s n- -ili( -at.ion. in the presence of two suhserihing witnesses. 

